Structure and Function of the Bacterial Primosome

摘要： DNA复制重启途径将细胞DNA复制复合物重新加载到 已提前终止的复制分叉，形成基本链接 DNA修复和复制之间的联系驱动这些反应的蛋白质， 作为原始体或复制重启蛋白，识别 放弃复制叉和重新加载DNA复制机制，特别是在 这些网站。复制重新启动过程经过调整，以确保加载保真度， 避免过度复制，这可能是由于在不合适的DNA上启动复制而引起的。 结构.尽管这一过程具有广泛的生物学重要性， 潜在的DNA复制重新启动及其调控仍然知之甚少。我们 建议结合结构，生物化学和遗传方法来定义结构 DNA复制的细胞机制重新启动。我们的总体目标是确定 管理这一过程的每一步的机制，从承认不同的 从废弃的DNA复制叉结构，到原始体组装，最后， 重新加载DNA复制机器。目标1将定义原始体的结构 复合物与复制叉，这将提供新的见解，结构特异性 识别DNA复制叉和调节DNA复制的机制 重启结构上的进步与遗传学研究相结合， 在细菌中的primosome蛋白的作用机制。Aim 2融合了结构和 遗传学研究的重点是primosome复合体的成熟及其在 将复制解旋酶重新装载回复制叉上。完成我们的具体 目的是确定介导和调节的分子和细胞机制， 细菌DNA复制重新开始。

Abstract: DNA replication restart pathways reload cellular DNA replication complexes onto replication forks that have been prematurely terminated, forming an essential link between DNA repair and replication. The proteins that drive these reactions, referred to as the primosome or the Replication Restart Proteins, recognize the structures of abandoned replication forks and reload the DNA replication machinery specifically at these sites. The replication restart process is regulated to ensure loading fidelity and to avoid over-replication that could arise from initiating replication at improper DNA structures. In spite of the broad biological importance of this process, the mechanisms underlying DNA replication restart and its regulation remain poorly understood. Our proposal combines structural, biochemical, and genetic approaches to define the structural and cellular mechanisms of DNA replication restart. Our overall objective is to determine the mechanisms that govern each step of the process, from recognition of diverse structures of abandoned DNA replication forks, to primosome assembly, and finally to reloading the DNA replication machinery. Aim 1 will define the structures of primosome complexes with replication forks, which will provide new insights into structure-specific recognition of DNA replication forks and the mechanisms that regulate DNA replication restart. Structural advances are coupled to genetic studies that will define the cellular mechanisms of action of primosome proteins in bacteria. Aim 2 blends structural and genetic studies to focus on maturation of primosome complexes and their activities in reloading the replicative helicase back onto replication forks. Completion of our specific aims will define the molecular and cellular mechanisms that mediate and regulate bacterial DNA replication restart.